Benchmark: Merge objects performance test

Tests:

Spread
let res = { email: "abc@mail.com", phone: "12345678", }; const b = { app_version: "AP.12", appsflyer_id: "askldjajkshdlkjh2323h4234j2l3j4h", advertising_id: "23;o4h2l34hl2kj3h4kj23h4", device_os_version: "12", device_name: "Aifon 15 PRO", firebase_instance_id: "2liu3hiuo23y4u23y4ui2y34iy3u4y234", }; const c = { first_name: "lalala", last_name: "dadada" }; res = { email: null, phone: null, last_name: null, first_name: null, app_version: null, appsflyer_id: null, advertising_id: null, device_os_version: null, device_name: null, firebase_instance_id: null, ...res, ...b }; res = { email: null, phone: null, last_name: null, first_name: null, app_version: null, appsflyer_id: null, advertising_id: null, device_os_version: null, device_name: null, firebase_instance_id: null, ...res, ...c }
Object.assign
let res = { email: "abc@mail.com", phone: "12345678", }; const b = { app_version: "AP.12", appsflyer_id: "askldjajkshdlkjh2323h4234j2l3j4h", advertising_id: "23;o4h2l34hl2kj3h4kj23h4", device_os_version: "12", device_name: "Aifon 15 PRO", firebase_instance_id: "2liu3hiuo23y4u23y4ui2y34iy3u4y234", }; const c = { first_name: "lalala", last_name: "dadada" }; res = { email: null, phone: null, last_name: null, first_name: null, app_version: null, appsflyer_id: null, advertising_id: null, device_os_version: null, device_name: null, firebase_instance_id: null, ...res }; Object.assign(res, b); Object.assign(res, c);
Foreach
let res = { email: "abc@mail.com", phone: "12345678", }; const b = { app_version: "AP.12", appsflyer_id: "askldjajkshdlkjh2323h4234j2l3j4h", advertising_id: "23;o4h2l34hl2kj3h4kj23h4", device_os_version: "12", device_name: "Aifon 15 PRO", firebase_instance_id: "2liu3hiuo23y4u23y4ui2y34iy3u4y234", }; const c = { first_name: "lalala", last_name: "dadada" }; res = { email: null, phone: null, last_name: null, first_name: null, app_version: null, appsflyer_id: null, advertising_id: null, device_os_version: null, device_name: null, firebase_instance_id: null, ...res }; Object.keys(b).forEach(key => { res[key] = b[key]; }); Object.keys(c).forEach(key => { res[key] = c[key]; });
just for
let res = { email: "abc@mail.com", phone: "12345678", }; const b = { app_version: "AP.12", appsflyer_id: "askldjajkshdlkjh2323h4234j2l3j4h", advertising_id: "23;o4h2l34hl2kj3h4kj23h4", device_os_version: "12", device_name: "Aifon 15 PRO", firebase_instance_id: "2liu3hiuo23y4u23y4ui2y34iy3u4y234", }; const c = { first_name: "lalala", last_name: "dadada" }; res = { email: null, phone: null, last_name: null, first_name: null, app_version: null, appsflyer_id: null, advertising_id: null, device_os_version: null, device_name: null, firebase_instance_id: null, ...res }; for (const key in b) { res[key] = b[key]; } for (const key in c) { res[key] = c[key]; }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Spread
Object.assign
Foreach
just for

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/132.0.0.0 Safari/537.36

Browser/OS: Chrome 132 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
Spread	5163386.5 Ops/sec
Object.assign	11650718.0 Ops/sec
Foreach	3487604.2 Ops/sec
just for	5712879.0 Ops/sec

Autogenerated LLM Summary (model llama3.2:3b, generated one year ago):

LLMs can make mistakes. Check important info.

Based on the provided benchmark results, I'll provide an analysis of the performance differences between three different methods: `Object.assign()`, `for...in` loop with `forEach()` (Foreach), and simple assignment.

**Method 1: Object.assign()**

* **Test Name:** "Object.assign"
* **Executions Per Second:** 4619255.0
* **Device Platform:** Desktop

The `Object.assign()` method is a modern JavaScript feature that allows assigning properties from one or more source objects to a target object. This approach is fast and efficient, requiring minimal overhead.

**Method 2: For...in loop with forEach() (Foreach)**

* **Test Name:** "Foreach"
* **Executions Per Second:** 3510965.0
* **Device Platform:** Desktop

The `for...in` loop with `forEach()` is a traditional JavaScript approach to iterating over objects. While it may seem slower compared to `Object.assign()`, the execution speed is still respectable, especially considering the explicit iteration.

**Method 3: Simple assignment**

* **Test Name:** "just for"
* **Executions Per Second:** 6470421.5
* **Device Platform:** Desktop

This method involves simple assignment of properties from two source objects (`b` and `c`) to a target object (`res`). While it might seem straightforward, this approach still exhibits decent performance.

**Key observations:**

1.  The order of the methods in terms of execution speed is `Object.assign()` > Simple Assignment > `For...in` loop with `forEach()`.
2.  Both `Object.assign()` and simple assignment are significantly faster than using a traditional `for...in` loop, which might be attributed to the inherent efficiency of modern JavaScript object manipulation.
3.  The performance difference between these methods is relatively small, especially considering the device platform (Desktop) and execution speed.

**Conclusion:**

In conclusion, based on the provided benchmark results, it appears that `Object.assign()` remains the fastest method for assigning properties from multiple source objects to a target object. While simple assignment and traditional loops (`for...in` with `forEach()`) are still respectable in terms of performance, they don't quite match the efficiency of `Object.assign()`.

Related benchmarks:

Merge objects performance test (version: 0)

Comparing performance of: Spread vs Object.assign vs Foreach vs just for

Created: 2 years ago by: Guest

Jump to the latest result

Spread

Object.assign

Foreach

just for

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated one year ago):